[SCSI] qla2xxx: Correct additional posting issues during NVRAM accesses.

On MMIO relaxed-order platforms, it is possible for the
proper delay during NVRAM access to begin before the request
passes through the PCI bus (via a MMIO write) to the ISP.
Thus, causing a subsequent read to the NVRAM part to fail.
Add a MMIO read, after the MMIO write to insure any posted
writes are flushed.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_sup.c b/drivers/scsi/qla2xxx/qla_sup.c
index 4bec0b4fb6b4..d54d2a99c3d3 100644
--- a/drivers/scsi/qla2xxx/qla_sup.c
+++ b/drivers/scsi/qla2xxx/qla_sup.c
@@ -126,6 +126,7 @@ qla2x00_write_nvram_word(scsi_qla_host_t *ha, uint32_t addr, uint16_t data)
 
         /* Wait for NVRAM to become ready */
         WRT_REG_WORD(&reg->nvram, NVR_SELECT);
+        RD_REG_WORD(&reg->nvram);               /* PCI Posting. */
         do {
                 NVRAM_DELAY();
                 word = RD_REG_WORD(&reg->nvram);
@@ -178,6 +179,7 @@ qla2x00_write_nvram_word_tmo(scsi_qla_host_t *ha, uint32_t addr, uint16_t data,
 
         /* Wait for NVRAM to become ready */
         WRT_REG_WORD(&reg->nvram, NVR_SELECT);
+        RD_REG_WORD(&reg->nvram);               /* PCI Posting. */
         do {
                 NVRAM_DELAY();
                 word = RD_REG_WORD(&reg->nvram);
@@ -235,6 +237,7 @@ qla2x00_nvram_request(scsi_qla_host_t *ha, uint32_t nv_cmd)
         /* Read data from NVRAM. */
         for (cnt = 0; cnt < 16; cnt++) {
                 WRT_REG_WORD(&reg->nvram, NVR_SELECT | NVR_CLOCK);
+                RD_REG_WORD(&reg->nvram);       /* PCI Posting. */
                 NVRAM_DELAY();
                 data <<= 1;
                 reg_data = RD_REG_WORD(&reg->nvram);
@@ -337,6 +340,7 @@ qla2x00_clear_nvram_protection(scsi_qla_host_t *ha)
 
                 /* Wait for NVRAM to become ready. */
                 WRT_REG_WORD(&reg->nvram, NVR_SELECT);
+                RD_REG_WORD(&reg->nvram);       /* PCI Posting. */
                 do {
                         NVRAM_DELAY();
                         word = RD_REG_WORD(&reg->nvram);
@@ -388,6 +392,7 @@ qla2x00_set_nvram_protection(scsi_qla_host_t *ha, int stat)
 
         /* Wait for NVRAM to become ready. */
         WRT_REG_WORD(&reg->nvram, NVR_SELECT);
+        RD_REG_WORD(&reg->nvram);               /* PCI Posting. */
         do {
                 NVRAM_DELAY();
                 word = RD_REG_WORD(&reg->nvram);